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#1151 2022-02-18 19:11:02

SpaceNut
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From: New Hampshire
Registered: 2004-07-22
Posts: 25,668

Re: Large scale colonization ship

I made a few posts on the topic on how to create a Space Radiation + counter measures shield.
I am currently re-reading for power source and amount which could be set aside for an semi active design.
Other types are a plasma and RF generated field but we do not have any experience with them in space.

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#1152 2022-02-18 21:28:01

tahanson43206
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Re: Large scale colonization ship

This is for RobertDyck ....

You've been consistent over two years, in setting the dimensions, operating characteristics and features of Large Ship.

I have tried to keep your ideas in mind, but the NewMars forum is a difficult place for memory to reside.

In the new Engineering topic, GW Johnson suggested an "Engineering Notebook" which we could create using the new Dropbox account.

I have memorized the width of the Large ship Habitat ring as 19 meters, and the circumference as 238 meters.
I have memorized the gravity prescription as Mars normal or .4 Earth standard.
I have memorized the atmosphere as 3-5-8, which is easy for a child to remember.
I have memorized the rotation as 3 RPM or 20 seconds per cycle.
I have memorized the axis of rotation as aligned with the center of the Sun.

As a working estimate for total ship's mass, we have 5,000 metric tons, which is a figure offered by GW Johnson for orbit calculations.

Beyond those key parameters, my memory is not reliable.

We are on the verge of gathering interest by others.  I noticed that even Calliban has mentioned Large Ship in a recent post.

It is up to you (should you decide to do so) to set the design parameters for Large Ship in a permanent storage location, such as the proposed Engineering Notebook that GW Johnson suggested.

I am looking for guidance on how to proceed, so the important design criteria are firmly in place before we bring a room full of college students into the mix.

As you can see by looking at GW's recent post, even he was unaware of your two years of steadfast development of the Large Ship.

I am doing all I can to help, but in the end, it is your opportunity to set the stage for group activity to follow.

(th)

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#1153 2022-02-19 09:54:18

SpaceNut
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Re: Large scale colonization ship

If the diameter of a starship of what is in the center roughly 10 meters. That leaves the transport tunnel length in the hub at about 15 meters in length for passengers to travel the length of with the effects of increasing gravity until you reach the floor to which you can stand on.

rotationFigure_07_02_01a.jpg

forcefigure-07-01-04a.jpeg

The rotating motion forces the crew against the rings outer wall that we need to stand up against.
http://www.physics.usyd.edu.au/~helenj/ … -rotor.pdf

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#1154 2022-02-19 10:24:15

tahanson43206
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Re: Large scale colonization ship

For SpaceNut .... C = pi * D
Pi is (approximately) 3.14159
238 / 3.14159 is >> 75.76~
The radius is 1/2 the diameter >> 37.88~

Please correct your post #1153

There is no reason to leave the post as it is.

It will be confusing to students who may read it in following the topic.

(th)

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#1155 2022-02-19 13:47:22

RobertDyck
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From: Winnipeg, Canada
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Re: Large scale colonization ship

Ring width: 19.12 metres (the extra 0.12 is the water wall)
Radius to floor of habitation ring: 37.6992 metres
Circumference: (Pi x D) = 236.871 metres (If the radius is to 6 significant figures, the circumference should be too. But that last "1" represents 1 millimetre.)
Rotation: 3 RPM
Artificial gravity: 3.72076 m/s² = 0.3794 G (37.94% that of Earth) which precisely equals Mars mean surface gravity (to 6 significant figures, that's where the radius came from)
Atmosphere: 2.7 psi O2, 3.5 psi N2, 1.14 psi Ar, add a little CO2 and water vapour, total pressure ½ Earth at sea level (7.34 psi)
Spacesuit pressure: 3.0 psi pure oxygen (Important for calculating nitrogen in ship's atmosphere. And ship's oxygen is 10% lower.)

Centrifugal Force Calculator: Omni Calculator or Keisan Online Calculator

Note: Ceiling is 2.43m (8 ft), if deck is 0.1m (4 inch) thick then radius to upper deck is 35.1692m. This makes artificial gravity 35.39497% Earth or 92.69% Mars.

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#1156 2022-02-19 15:51:26

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re #1155

Thanks for providing a concise set of specifications for Large Ship.

I have added a reference to Post #1155 in Post #3 of this topic, in case a future reader starts from the top, which I certainly hope happens.

I note that your post #2 clarified that Large Ship is NOT an Aldrin Cycler.  As recently as your Mars Convention presentation in 2021, you found yourself dealing with the powerful impression made by Buzz Aldrin with his concept.  Without a doubt you will be dealing with that ghost for some time to come.

Your opening text in your draft presentation to the March 12th audience addresses the issue.

However, just FYI ... the possibility that the Large Ship might become an accidental "cycler" came up in private correspondence with GW Johnson. If the Large Ship fails to slow to "dock" in Low Earth Orbit for any of a myriad of reasons, it will become a "cycler" although not a traditional one.

The passengers and crew can exit the vessel as it passes Earth, if fast ferries are on hand for the purpose, as I would expect them to be, because multiple copies of Large Ship will be in service in coming decades.

It is only common sense to plan for failure to "dock" at Earth, so providing for recovery of the passengers and crew is likely to be part of a business plan for Large Ship.

Thanks again for the specifications!

GW Johnson has introduced the idea of creating an Engineering Notebook for NewMars members (and others) to consult when planning work activities.

***
New subtopic ... not long ago you tossed out a suggestion that a 3D Virtual Environment for Large Ship might be constructed.  My first impression was that you might have been thinking of this as a substitute for building an actual model of the Large Ship habitat on Earth, but after reading more of posts by GW Johnson, I realized that an accurate rendering of the design would be valuable for engineers and architects working on the vessel.

This would be true for both the Earth based mockup, and for the flight-ready articles.

There are folks in this world who are highly skilled in 3D animation, and we may be lucky enough to enlist a small team willing to tackle rendering of this vessel.

(th)

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#1157 2022-02-19 16:39:12

SpaceNut
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Re: Large scale colonization ship

These measurements account for no wall thicknesses, crawl spaces between them, no tanks that might be within the them such as the batters and none for the materials to be used so approximate or about is used.

Which way does the floor and ceiling face, which way are the decks and internal walls between sections and chambers?
How are the items on the floor being attached, let along storage lockers for the items that are not anchored down?
So the bench will fit all passengers regardless or girth and door height will accommodate those that are tall so that they will not bump into them or how about the deck and sections seals for control of when fire or air leaks....
Where is the reactor or more, solar power source numbers and mass for batteries ect?
Then there is all the stuff that passengers will make use of plus brought with them for all sorts of ideas of what makes for the time for them to use?

rotation radius to rpmRotationSpeedOfCentrifuge.svg

https://space.nss.org/wp-content/upload … Globus.pdf

rotation rate (rpm)  radius (m)
1  895.47
2  223.87
3  99.50
4  55.97
5  35.82
6  24.87
7  18.27
8  13.99
9  11.06
10  8.95

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#1158 2022-02-19 19:51:48

RobertDyck
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Re: Large scale colonization ship

I said a few times that interior compartments are measured from centre-of-wall to centre-of-wall. Interior partition walls do not have to be 4" thick, this isn't wood. I'm thinking pressure bulkheads are sheet steel, made of two sheets with corrugated steel between. The sandwich must hold pressure if either side decompresses. Interior partition walls will be made of composite, also corrugated between flat wall surfaces. This allows walls to be much narrower. I'm thinking 2cm thick. Even with acoustic insulation. Remember the washroom is located adjacent to the corridor, and plumbing will be in a raceway along the ceiling of the corridor, so no plumbing in the walls.

A large box of equipment is located on the second level above each pressure compartment. That box is deliberately within a pressurized compartment so it can be serviced. This could be a box in the centre of an observation room, or greenhouse. The equipment box will have compressors for air conditioning, pressurized oxygen for emergency repressurization, electric storage batteries, and final water filtration to convert grey water to potable.

For an economy cabin, each bunk has a 10cm (4") deep storage compartment beneath the mattress. That storage compartment is the full length and width of the mattress. Plus 2 rows of drawers under the lower bunk, one row intended for the upper bunk, the other for the lower bunk. If someone rents a whole cabin, they could order one of the three bunk beds removed. that removed 2 bunks (upper & lower). That would free that much floor space for a chair, or just floor space to store luggage.

A studio single is different. Instead there's a Murphy bed, with desk surface beneath the bed the lifts up when the bed is folded into the wall. Along one wall of the cabin are cupboards for storage. Obviously luxury cabins have even more space.

The zero-G hub has an open space in front that acts as reception / foyer for passengers to embark / disembark. That space can be used as a zero-G gym or play area during transit. Aft of the zero-G hub is a zero-G cargo hold. That cargo hold will carry food and supplies for the trip, as well as spare parts for repairs & maintenance, some furniture for in-transit changes, and passenger cargo that they don't need access to during transit.

Floor is obviously the ring surface away from centre of rotation. Ceiling is "above" the floor, meaning closer to centre of rotation. Floor is curved, so that with rotation it feels flat. That is, floor is a constant distance from axis of rotation. Ceiling is also curved, again constant distance from axis of rotation. Walls are perfectly flat, vertical. Yes, this means width of the room along the floor is 2.43 metres (centre-of-wall to centre-of-wall), but width of the room along the ceiling is shorter.

Anchor points built into the steel floor, and into walls. The end wall, farthest from the door, is always metal. That end wall has anchor points for end tables, and Murphy bed. Side walls are composite for interior walls, steel for pressure bulkheads. Side walls have anchor points for upper bunks. For economy class cabins, the two lower bunks farthest from the door are mounted on rails, like rails of a car seat. These rails allow the bed to move left-right, and have 3 positions that lock into place. The rails attach to the floor anchor points. The beds attach to the rails. Beds can be all the way to the left, all the way to the right, or in the centre of the room. If beds are at opposite sides of the room, both end tables are attached to the end wall in the centre. They have to be attached to the end wall so they do not interfere with opening drawers under the bed. If both beds are in the centre position, they can have queen-size sheets so the two beds act as one. In that case, end tables are installed at opposite sides of the beds.  The lower bunk across from the bathroom has only one location, against the wall.

I did say the base design for this ship is solar panels for electrical power generation. I am assuming gallium-indium-nitride photovoltaic cells. These are the solar cells that I've posted about many times. From an article in the Journal Science from year 2000. The Los Alamos National Laboratory analyzed photovoltaic cells, and theoretically this chemistry should have a light absorption spectrum that almost perfectly matches the Sun's spectrum, so should be extremely efficient. They went to the University of California in Berkeley, materials lab, to build one to test if their theory matched reality. UC Berkeley found a 2-junction cell converted sunlight to electricity with 56% conversion efficiency, 3-junction with 64% efficiency, and theoretically a 36-junction cell should be 72% efficient. A later researcher optimized configurations for 2 thru 8 junctions. He confirmed 2-junction and 3-junction with the same efficiency, and calculated efficiency for 4-8 junctions. An 8-junction cell would be 70.2% efficient. So obviously the extra junctions for a 36-junction cell are not worth it. The best triple-junction cells for space right now use gallium-indium-phosphate for the top junction, so this new cell just replaces phosphate with nitride. Those best space cells currently are 32.2% efficient, so 70.2% efficiency is a significant improvement. Even if production cells are only 70.0% efficient Beginning-Of-Life, that's still very good. Spectrolab data says expect 84% power output after 15 years in GEO (US Standard AIAA S-111-2005), or 87% power (European standard-ECSS, Photon and temperature annealing according to ECSS-E-ST-20-08C).
Spectrolab XTE Standard Fluence datasheet

Notice the chloroplast oxygen generators are powered directly by sunlight. Plants in the greenhouse also use sunlight. So this reduces the amount of electrical power required to operate the ship.

Standard cabins have a wall for life support between the washroom and corridor. One question is whether space I've given is enough. With cabins 4 metres long by 2.43 metres wide (centre-of-wall), that leaves 2 metres of length per bunk. If composite walls are 2cm thick, that impinges 1cm on each of the 4 sides. If a bunk mattress is 75" (1.905cm) long, and pushed against one wall, then space between mattresses of beds (head to foot) is 17cm (6.69"). That's actually quite a bit. If a shower stall is 32"x32" (81.3cm square) then with 3cm (1 3/16") between end of bunk to shower stall, that leaves 1.232 metres for toilet & sink, plus life support wall. Is that enough? "Cupboard space" under the vanity counter would be for life support equipment. Space around the toilet would be for shower water recycling and toilet desiccation equipment. There may be an overhead "cupboard" space above the vanity for more life support equipment. Is that enough?

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#1159 2022-02-19 20:39:11

SpaceNut
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From: New Hampshire
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Posts: 25,668

Re: Large scale colonization ship

You have described an iso grid metal construction technique or sandwich for the hull.

https://en.wikipedia.org/wiki/Isogrid


https://etd.ohiolink.edu/apexprod/rws_e … ion=inline
STABILITY ANALYSIS OF ADDITIVELY MANUFACTURED ISOGRID

large.JPG

flat sheets are attached on either side to complete the construction for the hull.

So the ship once all are on will not have a starship with it going to mars docked with it?

Such that once in mars orbit a ship must dock with it to bring them to the surface of mars?

Your image
Uq9F6Sb.png

The top is the trailing or is this the mars return side of the ship that is facing the sun?

With the bottom of the center being the engines?

That means once we are heading to mars, we must flip the ship to have that side of it facing back towards the sun when we are going to mars?

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#1160 2022-02-19 21:42:44

RobertDyck
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From: Winnipeg, Canada
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Re: Large scale colonization ship

Yup. The bottom of this image is the stern, with engines. The top is the zero-G hub with docking port. A SpaceX Starship will launch from Earth to deliver passengers with their luggage. Once onboard, the Starship will return to Earth. The Large Ship travels to Mars without any Starship. Once in Mars orbit, a Starship must launch from Mars to dock with docking port (top of this image) to disembark passengers. So yes, that means the ship will depart Mars orbit with the stern toward Mars. That will not point the bow toward the Sun, but rather toward a trans-Earth trajectory. This will leave the ship roughly 90° to the Sun, so the ship will have to turn to point aft toward the Sun.
conjunction-class-mission.png

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#1161 2022-02-19 22:04:48

SpaceNut
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From: New Hampshire
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Posts: 25,668

Re: Large scale colonization ship

I was looking to see what surface the solar panels would be on and that appears to be the rings curved outer circumference that is 19m by 238 long around the ring. Even though its rotating only half will ever see the sun at any given moment and that half falls off after 1/3 of a center line in either direction. so only 2/3 of it has near full sun on it of that half of the ships ring. That is max power we can count on that as we head from earths starting point of about 1100 w / m^2 dropping as we head towards mars such that we are at about 550 watts / m^2. So if we design rooms and such to work with the lower amount we would have a good power level saved in batteries to make use of if we do need it.
That would be 1520 active panels at what ever panel efficiency is picked around the ring circuference, which is what we will have coming in to power everything.

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#1162 2022-02-19 22:38:21

RobertDyck
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From: Winnipeg, Canada
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Re: Large scale colonization ship

The surface of the floor of the habitation ring is 236.871 metres circumference. For the outside of the hull, you would have to add hull thickness. That will include the floor walking surface, the pressure hull, which must be strong enough to hold the weight of people standing on it plus the weight of all equipment inside. Outside the pressure hull will be multi-layer insulation for thermal insulation. Outside that is micrometeoroid protection. Outside that is radiators.

I had originally thought the solar panels would hang outboard (down) from the floor of the habitation ring on the aft side. That's the sun-ward side. However, after calculating how much sunlight the chloroplasts will require, that location will require large light-weight reflectors to collect sunlight into light pipes. The light pipes will shine sunlight through windows in the floor of the life support wall. So bags of chloroplasts can be illuminated by sunlight. This light is not for internal illumination, it's inside the life support wall, where the light is used by chloroplasts to convert CO2 & H2O into O2 and starch. So the solar panels had to be moved somewhere else. The obvious location is the space between the zero-G hub and the ring. Close to the ceiling of the ring will be reflectors for greenhouses. However, close to the zero-G hub we can have photovoltaic panels aka solar panels.

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#1163 2022-02-20 07:04:05

tahanson43206
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Re: Large scale colonization ship

For RobertDyck re #1162

Thank you for continuing to develop your vision !!!

You do not have time to read every post in the forum.

Unfortunately, this means you miss some posts that have a direct bearing on your project.

GW Johnson has stated (on more than one occasion) that the pressure hull must have NOTHING on it at all.

The reason is (or should be) obvious.... If a meteor or other object strikes the hull and delivers a puncture, your crew has a short time to find and plug the leak.

The Russians (relatively recently) had to deal with a small leak in one of their modules.  It was extremely difficult for them to find.

You will want to have the passengers and crew walking on surfaces at least two meters from the pressure hull.

You will NOT want to have equipment, water tanks, waste tanks or anything else on the pressure hull.

I'll adjust the text ... you may WANT to do all those things, but the safety inspectors who you MUST satisfy to receive a flight worthiness certificate will REQUIRE that the hull be clear for patching at any time.

(th)

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#1164 2022-02-20 08:53:52

SpaceNut
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Re: Large scale colonization ship

The micrometeor protection does hang on the outside of the hull as its the sacrificial item that will aid in the hull protection it is not placed inside of hull materials or layers.

The multi layer of thermal insulation is on the inside of the hull and it can be after an internal skin for this hull but before the wall interior of a cabin or other areas.

As for walking on the outer hull with plumbing or electrical running through it RobertDyck has the inner level deck floor ceiling as the area to carry all of this with in it so its that area that needs the extra depth or distance.

The light pipe starts with a sealed window that is made in layers of ceramic clear alumina like the ISS cupola of which I think the outer side of the hull would have a window protection system that can open or close to protect against micrometeor impacts. The light reflection tunnel will need to be thicker than those on earth and so will the inner diffusor glass but is about it.

With regards to material thickness and layering that is where prepared shaped panels can help with the assembly which seems to start with the central hub unit which seems to be an extended starship less internals. First would be the connects needed to make the transport elevator tunnels. Then the inner hull would be started to create the ring from the prepared iso grid panels which are shaped. Panels will need to have over lap to aid in the lacing of them to create strength. The next out side layer is staggered over these seams such to create that outer most hull.

All contents for the internals of the large ship must be made to bring through the tunnel as the elevator has not been installed yet. Once the outside hulls are complete the internal stuff can be done with out space suits as you have an air tight location to work in. Its one of the reasons why we want to have a shipyard in orbit. Basically a large box to build in.

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#1165 2022-02-20 10:54:08

tahanson43206
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Re: Large scale colonization ship

For SpaceNut .... re Post #164

Per GW Johnson, the insulation is outside the hull!

The inside of the hull must be clear.

Nothing at all should be glued or welded or bolted or in any other way fastened to the inside of the hull, with the sole exception of such structural members as are needed to support it with respect to the frame of the Large Ship.

There should be no objects of any kind stored or allowed to rest on the inside of the hull.

The inside of the hull MUST be clear at all times so holes can be patched quickly by crew members.

The crew members need room to be able to enter the space inside of the hull plating.

The floor of the habitat MUST be some distance above the inside surface of the hull.

(th)

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#1166 2022-02-20 13:04:58

SpaceNut
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Posts: 25,668

Re: Large scale colonization ship

A hull is not a single layer of metal but is a sandwich of an outer shell and one inner that has the insulation with in them to stop thermal conditions. Wall insulation is more of a sound with some thermal that allows for walls to have thing on them. The wall sections are removal-able so that you can fine the holes which are suspected to be behind them along the hull. Equipment is lined up on the inner walls that separate rooms near hallways and not on a hull outer wall for that reason. The panels that form room separators could be dissembled but are not needed to be moved. The only place is the equipment that covers the footprint for it on the floor unless is lifted off from the floor to allow for being able to get under it.

The hull ring has 4 surfaces of which any location with in the ship will only share 1 or 2 depending on if its a corner edge or an inner room location.

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#1167 2022-02-20 13:31:13

RobertDyck
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From: Winnipeg, Canada
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Re: Large scale colonization ship

tahanson43206 wrote:

You do not have time to read every post in the forum.

Unfortunately, this means you miss some posts that have a direct bearing on your project.

GW Johnson has stated (on more than one occasion) that the pressure hull must have NOTHING on it at all.

I did read that. Unfortunately it is not practical. The sunward hull must have the water wall directly inside the pressure hull. There is then a composite wall separating the cabin from the water wall. Remember the water wall is a bladder, aka plastic bag filled with water. That must be contained to keep it from slumping onto the floor. The composite wall is there to support the weight of the water, as well as act as the end wall of cabins on the sunward side.

The floor of the ring must have a walking surface of some sort. Do you really want to walk directly on the pressure hull? The walking surface is to protect the pressure hull from damage.

Interior cabin walls must have acoustic insulation to prevent sound from passing between cabins. Walls with the corridor will be composite, not pressure tight. For standard cabins, there will be 4 cabins across within a pressure compartment. The interior 2 cabins will have composite walls on both sides. The cabins adjacent to the pressure bulkhead will have a metal bulkhead on that side. Both composite walls and pressure bulkheads must have acoustic insulation. The bulkhead that separate subcompartments are the end wall of inside cabins (no window). They will require acoustic insulation.

ISS has a pressure hull with multi-layer insulation outside, and micrometeoroid insulation outside that. I propose building the hull of this ship the same way. Multi-layer insulation are multiple layers of aluminized Mylar with fishnet spacers between. The theory is the vacuum of space is the world's largest Thermos bottle, aka Dewar flask. The aluminized Mylar reflects radiant heat, the spacers are there to prevent (or minimize) heat transfer through conduction. Spacesuits use this, modules of ISS also use this. Micrometeoroid protection is done a couple ways, some modules have an outer layer of Orthofabric just like a spacesuit. The Leonardo module built by Italy uses a thin layer of sheet stainless steel.

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#1168 2022-02-20 13:49:10

SpaceNut
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Posts: 25,668

Re: Large scale colonization ship

Here is the cygnus image
?url=http:%2F%2Fnewatlas-brightspot.s3.amazonaws.com%2Farchive%2Forbital-crs-6-launch-6.jpg

It is using pressed sheets to give it strength and the panels are stronger due to the folds that are in them.
These are attached to a frame rib with fasteners.
You can still see the missing panels that there is an insulation within the systems of the inner hull to the outer.

https://www.nasa.gov/sites/default/file … erview.pdf
Micrometeoroid and Orbital Debris (MMOD) Risk Overview

thermal blankets
PIA18578-1600x1200.jpg

JEeoDDm.jpg

shuttle blanket
124483main_004_IMG_4419_hires.jpg

https://ntrs.nasa.gov/api/citations/201 … 016610.pdf
International Space Station Permanent Multi-purpose Module (PMM) Life Extension

https://ntrs.nasa.gov/api/citations/201 … hment=true
TEXTILES FOR LIVING IN SPACE

https://ntrs.nasa.gov/api/citations/199 … 047691.pdf
Multilayer Insulation Material Guidelines

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#1169 2022-02-20 16:50:41

GW Johnson
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From: McGregor, Texas USA
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Posts: 4,833
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Re: Large scale colonization ship

Conduction is conduction,  whether the atmosphere is vacuum or not.  The insulation layers will essentially care not whether they are on the inside or the outside of the pressure shell.  But patching leaks DOES care! 

Put the insulation,  and the meteor bumper layers,  and the solar radiation reflective foil,  on the outside of the pressure shell.  Then DO NOT hard-mount stuff to the inside of that pressure shell!  You simply MUST be able to reach,  and patch,  a leak quickly.  It is a fundamental safety thing!

I'm sorry,  but the Bigelow efforts prove conclusively that the insulation that you MUST HAVE also confers significant radiation-shielding effects.  That's actually good!  You need less of a "water wall" to have good shielding.  Not zero,  but less!

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#1170 2022-02-20 18:02:33

SpaceNut
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Re: Large scale colonization ship

Its quite thick from what I remember
https://en.wikipedia.org/wiki/B330

The wall thickness will be approximately 0.46 metres (18 in) when the module is fully expanded. The walls are made up of 24 to 36 layers for ballistic protection, thermal protection, radiation protection and will be as hard as concrete once the craft is fully expanded. The exterior will also feature four large windows coated with a UV protection film.

https://en.wikipedia.org/wiki/Bigelow_E … ity_Module

https://www.nasa.gov/feature/beam-facts-figures-faqs

https://space.nss.org/the-bigelow-expan … o-the-iss/

The BEAM’s skin is made up of multiple layers which include a layer of Vectran, a bulletproof fabric two times stronger than Kevlar. Vectran doesn’t tear if punctured, and tests have shown that micrometeoroids that would penetrate the walls of ISS only got halfway through the BEAM’s skin. Even if it is punctured, BEAM wouldn’t burst like a balloon. Just like any other ISS module, it would leak slowly enough to allow anyone inside to evacuate.

So what is the patching of that type of fabric leak?

Not any better than a metal can for radiation stopping at its thickness.

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#1171 2022-02-20 18:44:53

tahanson43206
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Re: Large scale colonization ship

For SpaceNut re #1170

Thanks for the details about the Bigelow foam/fabric wall.

It is ** so ** easy for us to miss details as we go along.

Your post seems to suggest the wall of the vessel would Not have a stainless steel hull as the pressure vessel.

I ** believe ** that GW Johnson is recommending the Bigelow material OUTSIDE the stainless steel pressure hull.

The issue that I ** think ** he is trying to address is the mistaken idea that anything could be placed on the inside of the pressure hull.

If I understand his advisory correctly, the inside of the pressure hull will be stainless steel, ** and ** will be kept clear of clutter of any kind, ** and ** there will be space above the pressure hull for crew to perform sealing activities as needed.

In other words, the equipment deck will be above the pressure hull, and the cabin deck will be above that.

It is important to keep in mind that water (and watery waste) will ** not ** go uphill by itself, so the equipment to manage those items needs to be below the living deck.

(th)

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#1172 2022-02-20 19:07:48

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 25,668

Re: Large scale colonization ship

GW was suggesting to use an inflatable to reduce mass without any metal at all and the complexity of the large ship plus the fact that no longer possible as Bigelow corporation has failed in the time frame of which the Beam unit was brought to the station and last year.

The sacrifice bags for micrometeors are made with kevlar and materials that will slow its penetration which are mounted on the outside of the hull..

Only the BNNT fabric is what slowed the radiation which KBD512 mentioned quite some time ago which is in the inflatable construction layers.


The outer floor at this time will not have any thing within it and plumbing will be of the suction variety to pull the water and waste into the sewer lines that will flow along the ceiling of the hallways is what is planned. The centripical force will move the water in the sink into the drain at which a valve can close to keep the water moving and air pressure can be applied to force it further into the line where it can be draw by pumps.

Both decks are mixed use cabins and many other things.

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#1173 2022-02-20 21:04:37

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 10,394

Re: Large scale colonization ship

For SpaceNut re #1172

OK ... we need GW Johnson to clarify.  My impression was that he was NOT suggesting substitution of the Bigelow technology for the stainless steel hull that ( I ** think **) RobertDyck is considering.

Instead, I ** think ** GW was suggesting use of the Bigelow material on the OUTSIDE of the stainless steel hull to prevent loss of thermal energy to space.

If you'll recall, the initial plan of RobertDyck was to place a stainless steel hull directly at the bottom of the cabins, so that little human feet would help to heat the Cosmos by radiating heat into the stainless steel, which would radiate it out to 50 Kelvin deep space.

GW Johnson recommended placing the Bigelow material on the OUTSIDE of the hull to help with thermal loss, but also to help with micrometeor activity and charged particle radiation.

It is good to see your thinking about the location of various floors.

I would like to see some decent (ie, machine drawn)_ diagrams for the March 12th presentation, if any of us can muster the time to make them.

If we had more Blender capable members we could pass models back and forth though the NewMars Dropbox facility.

On the other hand, Void and GW Johnson both produce impressive artwork using software other than Blender.

(th)

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#1174 2022-02-20 21:08:51

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 7,252
Website

Re: Large scale colonization ship

This is a very large ship. The mass of cabins and everything in the ship will be very significant. And this is not zero-G, this will use rotation to produce artificial gravity. That requires strength to support the weight of internal fixtures. You could use a fabric micrometeoroid layer outside the metal pressure hull, but I don't see TransHab working.

As for bare inside pressure hull: the floor will require a walking surface that is level, so that means consistent distance from centre of rotation. And you don't want constant wear on the pressure hull, so a walking surface (flooring) to protect the hull. However, the side of the ring will be the end wall of outside cabins on the forward side of the ship. That side has windows facing deep space. That wall could have wall paper to dampen sounds, so you aren't in a metal echo chamber, but nothing more. Thermal insulation will be outside the pressure hull. The ceiling could be similar: a mat coating sprayed on to the ceiling to dampen sounds, but nothing more. Realize, for a lot of the habitation ring, the ceiling will be a deck which forms the floor of the upper deck. When I estimated greenhouse size, it doesn't have to be full width of the ring. So corridors could have a vaulted ceiling, and outside cabins could have a vaulted ceiling as well. The curve would add strength to the pressure hull. But inside cabins will have a flat ceiling, which is the floor of the upper level. The bridge, laundry, brig, crew cabins, will all have flat ceilings because an observation room will be above. Will sickbay, or fine dining? Will have to work out detailed floor plan.

The side wall of the ring on the aft side is the issue. That is the end wall of outside cabins on that side. That wall is the water wall. That means a water bladder between a composite wall and the outer hull. Windows will pierce the water wall, so will have 2 panes filled with mineral oil. A window with mineral oil was used for radiation hot cells in the 1950s & 1960s, and I think still used today. The mineral oil is clear as water, but even lighter. It's a hydrocarbon; carbon has atomic weight 12.011, oxygen is 15.999. Lighter elements are better at stopping certain types of radiation. Between panes of glass, the mineral oil has very similar optical index as glass, so the window appears to be one thick pane. But like it or not, this means the water wall will cover that part of the pressure hull.

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#1175 2022-02-21 07:29:15

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 10,394

Re: Large scale colonization ship

For all ....

This topic is "Large Ship Prime" ....

It is stimulating creative thinking by members of this forum, as can be seen in the introduction of variations on the major theme introduced by ** this ** topic.

Recently I noted a post in another topic, expressing dismay at the size of the problem we are (collectively) addressing.  My message is to take heart, and simply identify the challenges ahead as they become clear.

The manager of ** THIS ** topic is RobertDyck.

He has provided specific guidelines for development of ** this ** topic.

Contributions we (members) make should (at least ** try ** to) help RobertDyck to advance his vision as far as it can go toward manifestation in the real-Universe.

We have several alternative concepts already blooming in the fertile soil of NewMars forum.

Please pay attention to the guidelines for each topic as you made contributions.

Regarding the challenge of propulsion for Large Ship ... let us quantify the requirements, and identify specific problems that need to be solved, document them in the appropriate topics, and resolutely move forward in the confidence that ultimately whatever challenges are identified ** will ** be overcome.

** Some ** version of Large Ship is most certainly going to fly.  I am supporting ** this ** one because (to the best of my knowledge) this is the ** only ** initiative along these lines on Earth.

(th)

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